Flexible device and operating methods thereof

ABSTRACT

A flexible device includes a flexible body and a plurality of piezoelectric materials arranged on the flexible body that deform in response to drive signals causing deformation of the flexible body of the flexible device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/784,565 filed on Oct. 16, 2017, which is a continuation of U.S.patent application Ser. No. 13/974,770 filed on Aug. 23, 2013, now U.S.Pat. No. 9,818,928, issued on Nov. 14, 2017, in the U.S. Patent andTrademark Office, which claims priority from Korean Patent ApplicationNo. 10-2012-0092609, filed on Aug. 23, 2012, in the Korean IntellectualProperty Office, the disclosures of which are herein incorporated byreference in their entireties.

BACKGROUND 1. Field

Devices and methods consistent with exemplary embodiments relate to aflexible device and operating methods thereof, and more particularly, toa flexible device which changes form using a plurality of piezoelectricsubstances and operating methods thereof.

2. Description of the Related Art

Advancement in the electronic technology has enabled development ofvarious types of electronic devices. Conventional display devices arewidely used, such as televisions, personal computers, laptop computers,tablets, mobile phones, and MP3 players.

To meet customer's desires for new devices, a ‘next-generation displaydevice’ is being developed.

One example of the next-generation display device is a flexible displaydevice. The ‘flexible display device’ refers to a display deviceconfigured to change its form.

The flexible display device may change form in response to a user'sforce exerted thereon.

Accordingly, a flexible device structure and operation method thereofare necessary to meet the user's various desires.

SUMMARY

Exemplary embodiments overcome the above disadvantages and otherdisadvantages not described above. Also, the exemplary embodiments arenot required to overcome the disadvantages described above, and anexemplary embodiment may not overcome any of the problems describedabove.

According to exemplary embodiments, a flexible device is provided thatcan change form using a plurality of piezoelectric substances, andoperating methods thereof.

According to an aspect of an exemplary embodiment, there is provided aflexible device including a flexible body, a lower piezoelectric layerof a first plurality of piezoelectric materials disposed on the flexiblebody, an intermediate layer disposed on the lower piezoelectric layer,an upper piezoelectric layer of a second plurality of piezoelectricmaterials disposed on the intermediate layer, and a flexible displaypanel supported by the flexible body.

The flexible device may additionally include a controller configured toapply a drive signal to at least one of the first plurality ofpiezoelectric materials of the lower layer and the second plurality ofpiezoelectric materials of the upper layer, the drive signal causing theat least one of the first plurality of piezoelectric materials andsecond plurality of piezoelectric materials to deform, in response todetecting an event.

The drive signal comprises a first drive signal and a second drivesignal, the at least one of the first plurality of piezoelectricmaterials and the second plurality of piezoelectric materials comprisesthe first plurality of piezoelectric materials and the second pluralityof piezoelectric materials, the first plurality of piezoelectricmaterials deform in a first direction, in response to application of thefirst drive signal to the first plurality of piezoelectric materials ofthe lower piezoelectric layer and the second plurality of piezoelectricmaterials deform in a second direction, in response to application ofthe second drive signal to the second plurality of piezoelectricmaterials of the upper piezoelectric layer, and the first plurality ofpiezoelectric materials and the second plurality of piezoelectricmaterials maintain a balanced state, in response to application of thefirst drive signal or the second drive signal to the first plurality ofpiezoelectric materials and the second plurality of piezoelectricmaterials.

The controller divides the first plurality of piezoelectric materialsand the second plurality of piezoelectric materials into a plurality ofgroups based on locations at which the first plurality of piezoelectricmaterials and the second plurality of piezoelectric materials aredisposed, and applies different ones of the first drive signal and thesecond drive signal to the respective groups to cause the grouped firstplurality of piezoelectric materials and the second plurality ofpiezoelectric materials to locally deform.

The flexible device may additionally include a display. The firstplurality of piezoelectric materials and the second plurality ofpiezoelectric materials are disposed on a lower portion of the display,the controller selectively applies the first drive signal and the seconddrive signal to the first plurality of piezoelectric materials and thesecond plurality of piezoelectric materials based on a type of theevent, and the controller controls the display to display a userinterface (UI) corresponding to a deformation state of the flexible bodycorresponding to the deformation of the first plurality of piezoelectricmaterials and the second plurality of piezoelectric materials on thedisplay.

The flexible device may additionally include a display, at least onebiosensor configured to detect a touch of a user arranged on lower sideof the display. The first plurality of piezoelectric materials and thesecond plurality of piezoelectric materials are disposed between thedisplay and the at least one biosensor, and the controller selectivelyapplies the first drive signal and the second drive signal to the firstplurality of piezoelectric materials and the second plurality ofpiezoelectric materials and controls the display to display a userinterface on the display, in response to the at least one biosensordetecting the touch of the user.

The first plurality of piezoelectric materials are disposed in acolumn-wise direction and the second plurality of piezoelectricmaterials are disposed in a row-wise direction.

The lower piezoelectric layer, the intermediate layer, and the upperpiezoelectric layer are stacked sequentially on one side of the flexiblebody.

The magnitude of the drive signal corresponds to a degree of deformationof the at least one of the first plurality of piezoelectric materialsand the second plurality of piezoelectric materials.

The flexible device may additionally include a detector configured todetect an electric signal generated from one or more piezoelectricmaterials of the first plurality of piezoelectric materials and thesecond plurality of piezoelectric materials in response to a deformationof the flexible body. The controller determines a deformation state ofthe flexible body based on a change in the electric signal and performsa control operation corresponding to the determined deformation state.

According to an aspect of an exemplary embodiment, there is provided amethod for operating a flexible device, which may include detecting, bya controller of the flexible device, occurrence of an event andselectively applying drive signals to a first plurality of piezoelectricmaterials of a lower piezoelectric layer disposed on a flexible body ofthe flexible device and a second plurality of piezoelectric materials ofan upper piezoelectric layer disposed on the first plurality ofpiezoelectric materials, based on the event. The drive signals causedeformation of the first plurality of piezoelectric materials and thesecond plurality of piezoelectric materials.

According to aspects of the exemplary embodiments, it is possible todeform the flexible device using a plurality of piezoelectric materials.As a result, utilization of flexible device further increases.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects will be more apparent by describing certainexemplary embodiments with reference to the accompanying drawings, inwhich:

FIG. 1 illustrates a constitution of a flexible device according to anexemplary embodiment;

FIG. 2 is a cross-section view of the flexible device of FIG. 1;

FIGS. 3 to 5 illustrates a constitution of one piezoelectric substanceaccording to various exemplary embodiments;

FIG. 6 is a view provided to explain bending of a piezoelectricsubstance in response to a first drive signal applied thereto;

FIG. 7 is a view provided to explain bending of a piezoelectricsubstance in response to a second drive signal applied thereto;

FIGS. 8 and 9 are views provided to explain how a flexible device changea form in response to bending piezoelectric substance;

FIG. 10 is a view provided to explain a situation when the same drivesignal is applied to an upper piezoelectric layer and a lowerpiezoelectric layer of a piezoelectric substance;

FIGS. 11 and 12 are views provided to explain a constitution to apply adrive signal to a piezoelectric substance;

FIGS. 13 and 14 are views provided to explain an example of an electrodepattern connected to a plurality of piezoelectric substances;

FIG. 15 is a block diagram provide to explain a constitution of aflexible device according to an exemplary embodiment;

FIGS. 16 to 20 are views provided to explain changing forms of aflexible device according to various exemplary embodiments;

FIG. 21 is a view provided to explain an operation of a flexible devicedisplaying a watch UI thereon;

FIG. 22 is a view provided to explain a constitution of a piezoelectricsubstance additionally including a biosensor;

FIG. 23 is a view provided to explain an arrangement pattern of aplurality of piezoelectric substances;

FIG. 24 illustrates a cross-section of the flexible device of FIG. 23;

FIG. 25 illustrates an arrangement pattern of a plurality ofpiezoelectric substances according to another exemplary embodiment;

FIG. 26 illustrates cross-section of the flexible device of FIG. 25;

FIG. 27 is a flowchart provided to explain an operating method ofchanging a form of a flexible device using a plurality of piezoelectricsubstances;

FIG. 28 is a block diagram provided to explain a constitution of aflexible device according to various exemplary embodiments;

FIG. 29 is a view provided to explain a constitution of software used inflexible device; and

FIG. 30 is a flowchart provided to explain an operating method ofcontrolling an operation of a flexible device by sensing a changed formof the flexible device using a plurality of piezoelectric substances.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Certain exemplary embodiments will now be described in greater detailwith reference to the accompanying drawings.

In the following description, same drawing reference numerals are usedfor the same elements even in different drawings. The matters defined inthe description, such as detailed construction and elements, areprovided to assist in a comprehensive understanding of the presentinventive concept. Accordingly, it is apparent that the exemplaryembodiments may be carried out without those specifically definedmatters. Also, well-known functions or constructions are not describedin detail because they would obscure the invention with unnecessarydetail.

FIG. 1 is a view provided to explain a constitution of a flexible deviceaccording to an exemplary embodiment. Referring to FIG. 1, the flexibledevice 1000 includes a body 100 and a plurality of piezoelectricsubstances 110-1˜110-n.

Respective components of the flexible device 100 are mounted to thebody, which is flexible and may be deformed.

The body may be made from plastic material (e.g., polymer film) that candeform in response to an external pressure. To be specific, the body 100may be configured as a base film coated on both surfaces with barriercoating. The base film may be formed from various resin such as, forexample, polyimide (PI), polycarbonate (PC), polyethyleneterephtalate(PET), polyethersulfone (PES), polythylenenaphthalaten (PEN), or fiberreinforced plastic (FRP). The barrier coating may be applied on bothsurfaces of the base film, respectively. Organic or inorganic film maybe used as the barrier coating to maintain flexibility. Additionally,the body 100 may be formed from various other materials exhibitingflexibility, such as, for example, a metal foil, etc.

The plurality of piezoelectric materials 110-1˜110-n may be mounted tosurface or interior of the body 100. To be specific, the plurality ofpiezoelectric materials 110-1˜110-n may be arranged at differentpositions of the body 100. FIG. 1 illustrates an example in which theplurality of piezoelectric materials 110-1˜110-n are formed atpredetermined intervals on one surface of the body 100 in horizontal andvertical rows, thus forming a matrix pattern. Although the piezoelectricmaterials 110-1˜110-n in the exemplary embodiment illustrated in FIG. 1are depicted at uniform intervals from each other, the number,locations, and pattern of arrangement of the piezoelectric materials110-1˜110-n are not restricted to any specific example, and may bevariously modifiable depending on application.

The plurality of piezoelectric materials 110-1˜110-n may be disposed inwhich two different piezoelectric layers are arranged. For convenienceof explanation, the piezoelectric layer on the upper portion is referredto as the ‘upper piezoelectric layer’, while the piezoelectric layerunder the upper piezoelectric layer is referred to as the ‘lowerpiezoelectric layer’.

The flexible device 1000 utilizes piezoelectric effect of the respectivepiezoelectric materials 110-1˜110-n. That is, when a user exertspressure by deforming the body 100 having the piezoelectric materials110-1˜110-n therein, the respective piezoelectric materials 110-1˜110-nare subject to dielectric polarization due to the exerted pressure, andthus generate electric signals. Therefore, direct piezoelectric effect,or a first piezoelectric effect occurs. On the contrary, with theapplication of electric field to the respective piezoelectric materials110-1˜110-n, the form of the piezoelectric materials 110-1˜110-n changesdue to the electric field, and this is an inverse piezoelectric effect,or a second piezoelectric effect. The effects mentioned above arecollectively referred to as the ‘piezoelectric effect’. According to anexemplary embodiment illustrated in FIG. 1, the flexible device 1000 canchange the form of the body 100 by using the piezoelectric effect, or tobe more specific, any combination of the first piezoelectric effect andthe second piezoelectric effect.

FIG. 2 illustrates a cross-section of the flexible device 1000 accordingto an embodiment. Referring to FIG. 2, the flexible device 1000 includesa display 120. The display 120 includes a first protective layer 121, adisplay panel 122, a driver 123, a backlight unit 124 and a substrate125.

The first protective layer 121 protects the display panel 122. Forexample, the first protective layer 121 may be formed from a material,such as ZrO, CeO₂, or ThO₂. The first protective layer 121 may be formedas a transparent film to cover the entire surface of the display panel122.

The display panel 122 may be implemented as a liquid crystal display(LCD), organic light-emitting diode (OLED), electrophoretic display(EPD), electrochromic display (ECD), or plasma display panel (PDP). Forimplementation as an LCD, the backlight unit 124, as illustrated in FIG.2, is necessary. The backlight unit 124 may include a light source, suchas lamps or an LED, in direct edge type arrangement, to providebacklight to the direction of the display panel 122.

The driver 123 drives the display panel 122. To be specific, the driver123 applies a driving voltage to a plurality of pixels of the displaypanel 122. The driver 123 may be implemented as a thin film transistor(TFT), low temperature poly silicon (LTPS) TFT, or organic TFT (OTFT).The driver 123 may take various configurations according to how thedisplay panel 122 is formed. For example, the display panel 122 mayinclude an organic light emitter of a plurality of pixel cells, andelectrode layers covering both surfaces of the organic light emitter.The driver 123 may include a plurality of transistors corresponding tothe respective pixel cells of the display panel 122. The respectivetransistors illuminate pixel cells connected thereto, with theapplication of electric signal thereto. As a result, an image isdisplayed on the display panel 122. Although not illustrated in FIG. 2,a color filter may additionally be provided. The respective componentsillustrated in FIG. 2 are fabricated into an organic structurecontaining carbon or a thin flexible structure, such as a foil.

The display 120 may alternatively be implemented as electric paper(e-paper). The e-paper may be implemented using semispheric twist ballscharged with electrostatic charge, an electrophoresis display methodusing electrophoresis and microcapsule, or a display method usingcholesterol liquid crystal.

The substrate 125 supports the components. The substrate 125 may be aplastic substrate formed from various material including, for example,polyimide (PI), polycarbonate (PC), polyethyleneterephtalate (PET),polyethersulfone (PES), polythylenenaphthalate (PEN), or fiberreinforced plastic (FRP).

The plurality of piezoelectric materials 110-1˜110-n are arranged underthe substrate 125 in various configurations.

The piezoelectric materials 110-1˜110-n are covered by the secondprotective layer 126. The second protective layer 126 may be formed froma flexible material, such as rubber or plastic. Although the exemplaryembodiment illustrated in FIG. 2 shows the second protective layer 126filling in gaps between the piezoelectric materials 110-1˜110-n, inanother exemplary embodiment, the gaps between the piezoelectricmaterials 110-1˜110-n may be left as empty spaces.

The piezoelectric materials 110-1˜110-n may be formed into variousconfigurations such as, for example, unimorph type, bimorph type orstack type. The ‘unimorph type’ refers to a configuration in which onepiezoelectric layer is stacked on disc-shaped metal layer. The ‘bimorphtype’ refers to a configuration in which two piezoelectric layers arestacked in sequence. The ‘stack type’ refers to a configuration in whichmetal electrode material is printed on ceramic sheet, after whichseveral sheets are compressed and the compressed structure includingelectrode therein is sintered.

FIG. 3 illustrates a cross-section of a unimorph type piezoelectricmaterial. Referring to FIG. 3, the unimorph type piezoelectric material110 includes a metal layer 112, and a piezoelectric layer 111 stacked onthe surface of the metal layer 112. In plan view, the metal layer 112and the piezoelectric layer 111 may have circular configuration. Thepiezoelectric layer 111 may be formed from piezoelectric ceramic orpiezoelectric polymer. For piezoelectric ceramic, various materials suchas PZT, PbTiO₃, BaTiO₃ are applicable.

With the application of drive signal of first polarity to thepiezoelectric layer 111, as illustrated, the edge area moves upward,while the central area moves downward. With the application of drivesignal of second polarity, which is opposite to the first polarity, theform is changed in the opposite manner.

FIG. 4 shows a cross-section of bimorph type piezoelectric material.Referring to FIG. 4, the bimorph type piezoelectric material 110includes an upper piezoelectric layer 111 and a lower piezoelectriclayer 113. The upper and lower piezoelectric layers 111, 113 areextended upon application of a first polarity drive signal, while theseconstrict upon application of a second polarity drive signal. The firstpolarity may be positive (+), and the second polarity may be negative(−). The piezoelectric material 110 bends to the direction of the secondpiezoelectric layer 113, when the first piezoelectric layer 111 isextended and the second piezoelectric layer 113 is constricted. On thecontrary, the piezoelectric material 110 bends to the direction of thefirst piezoelectric layer 111 when the first piezoelectric layer 111 isconstricted and the second piezoelectric layer 113 is extended.

FIG. 5 illustrates another example of constitution of a bimorph typepiezoelectric material. Referring to FIG. 5, an intermediate layer 114may be provided between the upper and lower piezoelectric layers 111,113 within the piezoelectric material 110.

The intermediate layer 114 may be formed from a flexible elasticmaterial. The intermediate layer 114 may have a shape of a rectangularparallelepiped with thin thickness. The upper piezoelectric layer 111 isstacked on the upper surface of the intermediate layer 114, and thelower piezoelectric layer 113 is stacked on the lower surface of theintermediate layer 114. As explained above, the upper and lowerpiezoelectric layers 111, 113 may be formed from various piezoelectricmaterials. Referring to FIG. 5, the upper and lower piezoelectric layers111, 113 may be configured to partially cover the intermediate layer114. That is, the intermediate layer 114 may be formed to have a longerlength. The lengths of the respective piezoelectric layers 111, 113 andthe intermediate layer 114 may be determined based on the data measuredthrough experiments.

For example, the frequency and displacement according to the length ofthe intermediate layer 114 may be measured as follows by the experiment.

TABLE 1 Int. Layer(mm) 80 90 100 110 120 Piezo. Layer (mm) 30 30 30 3030 Frequency (Hz) 40.621 32.389 24.845 20.045 19.875 Displacement (mm)8.64 12.92 13.78 6.44 6.545

Table 1 lists displacements measured by varying the length of theintermediate layer 114 to 80, 90, 100, 110, 120 mm under the conditionthat each end of the piezoelectric layers 111, 113 and intermediatelayer 114 is aligned to each other, and the lengths of the piezoelectriclayers 111, 113 are fixed at 30 mm. According to Table 1, the maximumdisplacement is measured when the length of the intermediate layer 114is 100 mm, which is shorter than the maximum length (i.e., 120 mm). The‘displacement’ refers to a width δ of the other end of the intermediatelayer 114 deformed in upward and downward direction.

The displacement may be expressed by the following mathematical formula.δ=k·d ₃₁ ·V·l ² ·/t ²  <Mathematical Formula 1>

where, δ denotes displacement, k is integer, d₃₁ is piezoelectricconstant, V is applied voltage, l is length of piezoelectric layer, andt is thickness. According to Mathematical Formula 1, the displacement δincreases in proportion to applied voltage, i.e., to drive signal.

Although FIG. 5 illustrates that the intermediate layer 114 to be longerthan the piezoelectric layers 111, 113, in another exemplary embodiment,the lengths of the intermediate layer 114 and the piezoelectric layers111, 113 may be equal. Further, the direction of the piezoelectricmaterial 110 bending may be determined according to a voltage differencebetween the first drive signal applied to the upper piezoelectric layer111 and the second drive signal applied to the lower piezoelectric layer113.

A method for adjusting a direction of deformation of the piezoelectricmaterial 110 inclusive of the upper piezoelectric layer 111, theintermediate layer 114, and the lower piezoelectric layer 113 in equallength will be explained below with reference to FIGS. 6 and 7.

Referring first to FIG. 6, the first drive signal V1 is applied to theupper piezoelectric layer 111, and the second drive signal V2 is appliedto the lower piezoelectric layer 113. The upper piezoelectric layer 111extends and the lower piezoelectric layer 113 contracts when the firstdrive signal V1 is positive (+), and the second drive signal V2 isnegative (−). As a result, the piezoelectric material 110 bends in thefirst direction. The piezoelectric material 110 may bend in the firstdirection even when V1 and V2 have same polarity, if V1 is larger thanV2.

FIG. 7 illustrates a situation where V1 and V2 are applied in oppositedirection to that illustrated in FIG. 6. According to FIG. 7, thepiezoelectric material 110 bends to the second direction which isopposite to the first direction.

When the piezoelectric material 110 bends as illustrated in FIGS. 6 and7, the body 110 of the flexible device 1000 to which the piezoelectricmaterial 110 is attached also bends.

FIG. 8 illustrates a situation in which the body 100 bends in the firstdirection when the piezoelectric materials 110-1˜110-n mounted to thebody 100 bend in the first direction, as illustrated in FIG. 6.Conversely, FIG. 9 illustrates a situation in which the body 100 bendsin the second direction when the piezoelectric materials 110-1˜110-nmounted to the body 100 bend in the second direction, as illustrated inFIG. 7.

Meanwhile, the upper and lower piezoelectric layers 111, 113 both havethe same piezoelectric effect when the same drive signal is applied tothe upper and lower piezoelectric layers 111, 113.

FIG. 10 illustrates a situation in which the same drive signal isapplied. Referring to FIG. 10, the respective piezoelectric materials110 maintain a balanced state and extend lengthwise, when the (+)polarity first drive signal V1 is applied to the upper and lowerpiezoelectric layers 111, 113. Accordingly, the gap (g) between therespective piezoelectric materials decreases, as illustrated in FIG. 10,thus creating a compressive effect and reinforcing the body 100 of theflexible device 1000.

FIGS. 11 and 12 are views provided to explain various examples of astructure to apply a drive signal of a bimorph type piezoelectricmaterial.

Referring to FIG. 11, the piezoelectric material 110 includes an upperpiezoelectric layer 111, an intermediate layer 114, a lowerpiezoelectric layer 113, a first electrode 115-1 disposed on an uppersurface of the upper piezoelectric layer 111, a second electrode 115-2disposed between the upper piezoelectric layer 111 and the intermediatelayer 114, a third electrode 115-3 disposed between the intermediatelayer 114 and the lower piezoelectric layer 113, and a fourth electrode115-4 disposed on a lower surface of the lower piezoelectric layer 113.

Referring to FIG. 11, a (+) polarity electric field is formed on theupper piezoelectric layer 111, when (+) voltage is applied to the firstand fourth electrodes 115-1, 115-4, and (−) voltage is applied to thesecond and third electrodes 115-2, 115-3. As a result, the piezoelectricsubstance within the upper piezoelectric layer 111 polarizes accordingto the direction of the electric field, and the length of the crystalsextends. That is, the upper piezoelectric layer 111 extends lengthwise.On the contrary, (−) polarity electric field is formed on the lowerpiezoelectric layer 113. Accordingly, the lower piezoelectric layer 113constricts lengthwise. As a result, the piezoelectric material 110 bendsto the direction of the lower piezoelectric layer 113, as illustrated inFIG. 11.

FIG. 12 illustrates an arrangement in which electrodes are provided onupper and lower sides of the piezoelectric material 110. Referring toFIG. 12, the piezoelectric material 110 includes an upper piezoelectriclayer 111, an intermediate layer 114, a lower piezoelectric layer 113, afirst electrode 116-1 disposed on an upper surface of the upperpiezoelectric layer 111, and a second electrode 116-2 disposed on alower surface of the lower piezoelectric layer 113. Accordingly, when(+) signal is applied to the first electrode 116-1 and (−) signal isapplied to the second electrode 116-2, the upper piezoelectric layer 111extends and the lower piezoelectric layer 113 constricts, so that thepiezoelectric material 110 bends downward.

An electrode pattern may be provided to apply an individual drive signalto the upper and lower piezoelectric layers, respectively. The electrodepattern electrically connects electrodes connected to the upper andlower piezoelectric layers to an internal power circuit of the flexibledevice 1000. The electrode pattern may be formed on a lower portion ofthe substrate 125, as explained above, or within the second protectivelayer 126. Alternatively, the electrode pattern may be provided withinthe substrate 125 when a plurality of piezoelectric materials110-1˜110-n are embedded in the substrate 125.

FIG. 13 illustrates an electrode pattern according to an exemplaryembodiment. Referring to FIG. 13, the flexible device 1000 includesupper electrode patterns 117-1, 117-3, 117-5 connected to the upperpiezoelectric layer 111 of each of the piezoelectric materials110-1˜110-n, and lower electrode patterns 117-2, 117-4, 117-6 connectedto the lower piezoelectric layer 113 of each of the piezoelectricmaterials 110-1˜110-n.

The upper electrode patterns 117-1, 117-3, 117-5 and the lower electrodepatterns 117-2, 117-4, 117-6 commonly connect the piezoelectricmaterials arranged on the same rows. That is, the first upper electrodepattern 117-1 is commonly connected to the lower piezoelectric layers113 of the first, fourth, and seventh piezoelectric materials 110-1,110-4, 110-7 arranged on the first row. Likewise, the piezoelectricmaterials arranged on the remaining rows are also commonly connected bythe upper and lower electrode patterns corresponding to the rows of thepiezoelectric materials.

The upper and lower electrode patterns 117-1, 117-3, 117-5, and 117-2,117-4, 117-6 are connected to electrode pads 118-1˜118-6. Accordingly,when a drive signal is applied to one electrode pad, the same drivesignal may be provided to the piezoelectric materials which are commonlyconnected to the electrode pattern connected to the electrode pad inreceipt of the drive signal.

FIG. 13 illustrates a situation where the piezoelectric materials areimplemented in multi-layer structure. In one exemplary embodiment, theupper electrode patterns 117-1, 117-3, 117-5 may be formed on the samelayer as the upper piezoelectric layer 111, and the lower electrodepatterns 117-2, 117-4, 117-6 may be formed on the same layer as thelower piezoelectric layer 113. That is, the upper electrode patterns117-1, 117-3, 117-5 may be formed on upper layer than the lowerelectrode patterns 117-2, 117-4, 117-6, as is illustrated in FIG. 13, inwhich the upper electrode patterns 117-1, 117-3, 117-5 are illustratedin solid lines, and the lower electrode patterns 117-2, 117-4, 117-6 areillustrated in dotted lines. Depending on application, a penetratingelectrode may be extended through the layers.

In addition to the exemplary embodiment illustrated in FIG. 13, in whicha plurality of piezoelectric materials are arranged in matrix patternand driven in row-wise manner, alternative embodiments are possible. Forexample, the plurality of piezoelectric materials may be driven incolumn-wise manner, in which case upper electrode patterns (notillustrated) to commonly connect the upper piezoelectric layers (e.g.,first, second, and third) arranged in columns, and lower electrodepatterns (not illustrated) to commonly connect the lower piezoelectriclayers of the piezoelectric materials arranged in columns, may beadditionally provided. Further illustration and explanation about thecolumn-wise electrode patterns will be omitted for the sake of brevity,as the artisan of ordinary skill will be easily able to understand thearrangement of the electrode patterns based on the row-wise, upper andlower electrode pattern. Although FIG. 13 illustrates only three upperelectrode patterns, depending on embodiments, the number of electrodepatterns may vary according to the number of piezoelectric materials.

Further, although FIG. 13 particularly illustrates an example in which aplurality of piezoelectric materials in row-wise or column-wisearrangement are uniformly driven, the piezoelectric materials may bedriven as certain piezoelectric material unit.

FIG. 14 illustrates an electrode pattern to drive a unit ofpiezoelectric material according to an embodiment.

Referring to FIG. 14, a plurality of upper electrode patterns 117-1 a,117-1 b, 117-1 c, 117-3 a, 117-3 b, 117-3 c, 117-5 a, 117-5 b, 117-5 care individually connected to the upper piezoelectric layer of eachpiezoelectric material. Further, a plurality of lower electrode patterns117-2 a, 117-2 b, 117-2 c, 117-4 a, 117-4 b, 117-4 c, 117-6 a, 117-6 b,117-6 c are individually connected to the lower piezoelectric layer ofeach piezoelectric material. Further, the upper and lower electrodepatterns are connected to corresponding electrode pads 118-1 a, 118-1 b,118-1 c, 118-2 a, 118-2 b, 118-2 c, 118-3 a, 118-3 b, 118-3 c, 118-4 a,118-4 b, 118-4 c, 118-5 a, 118-5 b, 118-5 c, 118-6 a, 118-6 b, 118-6 c.The flexible device 1000 may deform the body 100 to a desired state, byapplying a drive signal to the electrode pads connected to thepiezoelectric materials at a location intended for deformation. Thedeformation operation will be explained in detail below.

FIG. 15 is a block diagram of a flexible device according to anexemplary embodiment. Referring to FIG. 15, the flexible device 1000includes a plurality of piezoelectric materials 110-1˜110-n, a display120, a controller 130, a storage 140, a driver 150 and a bus 160.

The structure and a method for driving a plurality of piezoelectricmaterials 110-1˜110-n will not be additionally explained, but referencedto the above corresponding description.

The display 120 is formed from flexible material and performs variousdisplay operations under control of the controller 130.

The driver 150 is configured to apply a drive signal to a plurality ofpiezoelectric materials 110-1˜110-n. The driver 150 may generate drivesignals of different sizes and polarities, using the power provided froma battery (not illustrated). The drive signal may be generated in theform of pulse signal.

The storage 140 stores an operating system (O/S) that controls theoperation of the flexible device 100, applications, and other data. Thecontroller 130 is driven by the O/S stored at the storage 140 to executevarious applications.

The bus 160 is configured to transmit and receive data, or controlsignal among the respective components of the flexible device 1000. Thebus 160 may include an address bus, a data bus, or a control bus. Theaddress bus is used to transmit and receive address-related information,such as memory address, and the data bus is a bus system which connectsthe controller 130, the storage 140, and the other input/output for dataexchange. The control bus is a bus system used by the controller 130,the storage 140, or the other components to transmit or receive variouscontrol signal. The control signal may include a memory sync signal,input/output sync signal, driving control signal, CPU status signal,interrupt request and permission signal, or clock signal.

The controller 130 controls the overall operation of the flexible device1000 according to user manipulation. To be specific, upon receiving aturn-on command, the controller 130 may execute initialization programto boot up the flexible device 1000 and displays a background screenthrough the display 120. The background screen may include icons forvarious functions, applications, or folders. When a user selects oneamong the icons, the controller 130 performs a corresponding operationaccording to the selected icon.

When a preset event occurs, the controller 130 may control the driver150 to apply a drive signal to at least one among the plurality ofpiezoelectric materials 110-1˜110-n. To be specific, the controller 130may provide the driver 150 with address signal to designatepiezoelectric material to be driven among the respective piezoelectricmaterials 110-1˜110-n via the address bus, and also provides the driver150 with direction signal to designate the order of driving via thecontrol bus.

The driver 150 sequentially applies drive signal to the piezoelectricmaterial as designated by the address signal, in accordance with thedirection signal. The driver 150 may determine a point of driving therespective piezoelectric materials based on the clock signals.

The piezoelectric materials in receipt of the drive signal bend to apredetermined direction according to the characteristic of the drivesignal, and as a result, the body 100 area where the correspondingpiezoelectric materials are located, bend as well. Accordingly, the body100 changes a form.

As explained above, the piezoelectric materials 110-1˜110-n may bearranged in various patterns in the body 100. With reference to thelocations of the respective piezoelectric materials 110-1˜110-n in theentire area of the flexible device, the controller 130 may divide theplurality of piezoelectric materials into a plurality of groups. Forexample, referring to FIG. 13, when piezoelectric materials 110-1˜110-nare arranged in a plurality of columns and rows, the piezoelectricmaterials may be grouped in columns or rows. The controller 130 locallydeforms the flexible device 1000 by applying different drive signals tothe respective groups.

The location, direction or degree of deformation may vary depending onthe types of events. The event may include an event to execute aspecific application, an event to turn on the power of the flexibledevice 1000, an event that a user selects a deform menu, an event ofreceiving new message, mail, messenger, or call, an event to generateinformation message, or an event to generate error message.

For example, with reference to the piezoelectric material arrangement asthe one illustrated in FIG. 13, the controller 130 may apply respectivedrive signals to the first and second electrode pads 118-1, 118-2 todrive the piezoelectric materials 110-1, 110-4, 110-7 arranged on thefirst row, to bend the left edge area of the flexible device 1000 to afirst or second direction. Accordingly, as the piezoelectric materials110-1, 110-4, 110-7 on the first row bend to the same direction, thebody 100 area bends at the left edge where the piezoelectric materials110-1, 110-4, 110-7 are arranged.

Meanwhile, when the flexible device 1000 includes the display 120 as inthe example illustrated in FIG. 15, the controller 130 may control thedisplay 120 to display a UI screen corresponding to deformation of thebody 100, when the body 100 deforms. That is, while deforming the body100 including the display entirely or partially to a preset form byapplying a drive signal to the piezoelectric materials according to typeof the event, the controller 130 may control the display 120 to displaya certain type of UI screen suitable for the deformation to display thedeformation state in appropriate location, size or color.

Although FIG. 15 illustrates a flexible device which includes thedisplay 120, a certain type of flexible device 1000 may not include thedisplay 120.

The controller 130 may deform the body 100 to various forms, by applyingvarious drive signals to the respective piezoelectric materials110-1˜110-n.

FIGS. 16 to 20 illustrate deformations of the flexible device 1000.Referring to FIG. 16, the flexible device 1000 may be deformed byrolling. The controller 130 may control the driver 150 to apply a firstdrive signal (V1) to the upper piezoelectric layers of the plurality ofpiezoelectric materials 110-1˜110-n arranged on the entire area of theflexible device 1000, and to apply a second drive signal (V2) to thelower piezoelectric layers. Accordingly, the piezoelectric materials110-1˜110-n bend in the direction of the lower piezoelectric layers, andthus rolling both ends of the body 100 close to contact to each other.

The controller 130 may adjust the degree of deformation of the flexibledevice by adjusting a size of the drive signal. That is, the body 100may be rolled when the potential difference between V1 and V2 is large,but the body 100 may be deformed to the extent as illustrated in FIG. 8when the potential different is reduced. Accordingly, the controller 130may determine whether the event indicates to roll the flexible device1000, as illustrated in FIG. 16, or to bend the flexible device 1000 towithin a predetermined radius of curvature, as illustrated in FIG. 8,and accordingly adjust the size of the drive signal. The driver 150generates a drive signal of the size controlled by the controller 130and outputs the generated signal to the respective piezoelectricmaterials 110-1˜110-n.

FIGS. 17 and 18 illustrate an example in which the flexible device 1000deforms differently depending on areas. Referring to FIG. 17, thecontroller 130 divides the area of the flexible device 1000 intosub-areas (a), (b), (c). The controller 130 controls the driver 150 toapply V2 to the upper piezoelectric layer and V1 to the lowerpiezoelectric layer for the piezoelectric materials arranged in area(a), to commonly apply V1 to both upper and lower piezoelectric layersfor the piezoelectric materials arranged in area (b), and to apply V1 toupper piezoelectric layer and V2 to lower piezoelectric layer for thepiezoelectric materials arranged in area (c). As a result, area (a)bends to the first direction, area (b) maintains balance, and area (c)bends to the second direction.

FIG. 19 illustrates another example of the flexible device 1000employing local deformation. Referring to FIG. 19, the controller 130divides the entire area of the flexible device 1000 into sub-areas (a),(b), (c). The controller 130 controls the driver 150 to commonly applythe same drive signal V1 to both the upper and lower piezoelectriclayers for the piezoelectric materials arranged in areas (a) and (c),and apply V1 to upper piezoelectric layer and V2 to lower piezoelectriclayer for the piezoelectric materials arranged in area (b). As a result,areas (a), (c) maintain balanced state and thus are reinforced, whilethe area (b) bends to the first direction. Accordingly, the flexibledevice 1000 deforms to a form like the hard cover of a book.

FIG. 20 illustrates the flexible device 1000 employing local deformationaccording to another exemplary embodiment Like the exemplary embodimentillustrated in FIG. 19, the exemplary embodiment of FIG. 20 alsocommonly apples the same drive signal (V1) to the upper and lowerpiezoelectric layers for the piezoelectric materials arranged in areas(a), (c), while applying V1 to the upper piezoelectric layer and V2 tothe lower piezoelectric layer for the piezoelectric materials arrangedin area (b). The difference from FIG. 19 is that the potentialdifference is down-adjusted to reduce degree of deformation. That is, asthe radius of curvature of area (b) in FIG. 20 is adjusted to be lessthan that of area (b) of FIG. 19, the flexible device 1000 is deformedto a form representing the outer part of a laptop computer.

As illustrated in FIGS. 16 to 20, it is possible to set the deformationstate of the flexible device 1000 according to applications or functionsto provide user convenience or meet user satisfaction using theapplications or functions. Accordingly, the storage 140 may storeinformation about a deformation state, and applications or setupinformation matching the deformation state. The controller 130 controlsthe driver 150 to apply a drive signal that suits the circumstance,based on the information stored at the storage 140.

For example, the driver 150 is controlled to implement the deformationas illustrated in FIG. 16 when a telephone call is received, or asillustrated in FIG. 17 when a specific game program is executed, or asillustrated in FIG. 18 when mail or message is received. The driver 150is also controlled to implement the deformation as illustrated in FIG.19 when an e-book or gallery program is executed, or as illustrated inFIG. 20 when word-processor program is executed.

The controller 130 may control the display 120 to display an appropriateuser interface (UI) screen upon deformation. For example, when theflexible device 1000 deforms, as illustrated in FIG. 16, the display 120may display the UI screen in the telephone receiver shape, or display agame screen with the deformation like the one illustrated in FIG. 17.The display 120 may display a screen to check mail or message in area(b) with the deformation illustrated in FIG. 18, or may display a screenof an e-book or gallery program with the deformation illustrated in FIG.19. The controller 130 may cause the display to display word inputwindow in area (a), and soft keyboard in area (c), with the deformationillustrated in FIG. 20. The controller 130 may cause the display todisplay texts, symbols, or figures as inputted through the soft keyboardin the word input window. Accordingly, the user is able to use theflexible device 1000 as if using a laptop computer.

FIG. 21 is a view provided to explain an example of using the flexibledevice 1000 according to an exemplary embodiment.

Referring to FIG. 21, the flexible device 1000 is plane when in standbymode. When an operator's body (OB) touches a surface of the flexibledevice 1000, the controller 130 drives the piezoelectric materialsarranged on the entire area of the flexible device 1000 so that theflexible device 1000 rolls around the operator's body OB to mimic theshape of a wrist watch. At the same time, the controller 130 displays awatch UI through the display 120. The watch UI may be displayed on theentire area of the display 120, or alternatively, limitedly displayedaround the center of the display 120 as illustrated in FIG. 21.

Although the exemplary embodiment illustrated in FIG. 21 exemplifies asituation where the flexible device 1000 operates as a wrist watch,different functions are equally implementable. For example, referring toFIG. 21, when the operator's body OB touches a surface of the flexibledevice 1000, the flexible device 1000 may automatically execute MP3playback function, while displaying through the display 120 a screen toindicate the playback state. Further, when the flexible device 1000includes an exercise sensor, the calorie-tracker function may beautomatically executed, and a screen indicating exercises performed,calories burned, etc. as measured by the calorie-tracker function may bedisplayed through the display 120.

A touch sensor or a biosensor may be arranged on a rear surface of theflexible device 1000 to detect a touch of the operator's body OB, asillustrated in FIG. 21.

FIG. 22 is a cross-section view provided to explain a constitution of aflexible device 1000 including a biosensor. Referring to FIG. 21, theflexible device 1000 includes a display 120, a piezoelectric material110, and a biosensor 170. The biosensor 170 may be arranged on a lowerside of the display 120, and the piezoelectric material 110 may bearranged between the display 120 and the biosensor 170.

Although FIG. 21 illustrates one piezoelectric material 110 and thedisplay 120 layered above for convenience of explanation, in actualimplementation, a plurality of piezoelectric materials 110 may bedistributed across the entire area of the display 120.

The biosensor 170 is arranged under the piezoelectric materials 110. Thebiosensor 170 may be an electrodermal response (EDA) sensor, orelectromuscular response (EMG) sensor.

Although FIG. 22 illustrates the biosensor 170 in the same size and atthe same location as the intermediate layer 114 of the piezoelectricmaterials 110, an exemplary embodiment is not limited to any specificexample only. Accordingly, the biosensor 170 may be placed at anylocation as long as the biosensor 170 is exposed through the lowersurface of the body 110 of the flexible device 1000 to directly touchthe operator's body (OB). Further, the number and configuration of thebiosensor 170 may be varied depending on purpose of the design. In oneexemplary embodiment, a plurality of biosensors 170 may be provided atintervals with each other on the rear surface of the flexible device1000.

The controller 130 rolls the flexible device 1000 by applying differentdrive signals to the upper and lower piezoelectric layers of theplurality of piezoelectric materials, when the biosensor 170 senses theOB's touch. When there are a plurality of biosensors 170, the flexibledevice 1000 may be rolled when the entire or more than certain number ofbiosensors 170 sense the OB's touch.

When the flexible device 1000 is rolled, the controller 130 may displayvarious types of UI screens, such as watch UI, content playback screen,playback progress indicator screen, or exercise counter screen, on atleast one area of the display 120.

Meanwhile, although the exemplary embodiments explained above includethe piezoelectric materials 110-1˜110-n in the same size and shape, andparticularly, arranged in the same direction, the direction of arrangingthe piezoelectric materials may vary depending on embodiments.

FIG. 23 illustrates a piezoelectric material arrangement pattern of theflexible device according to another exemplary embodiment. Referring toFIG. 23, the body 100 includes a plurality of first piezoelectricmaterials 110-H11, 110-H12, 110-H13, 110-H14, 110-H21, 110-H22, 110-H23,110-H24, 110-H31, 110-H32, 110-H33, and 110-H34 arranged in column-wisedirection (H1, H2, H3), and a plurality of second piezoelectricmaterials 110-V11, 110-V12, 110-V21, 110-V22, 110-V31, 110-V32 arrangedin row-wise directions (V1, V2, V3). The longer axis of the firstpiezoelectric material is orthogonal to the longer axis of the secondpiezoelectric material. Accordingly, the operation is not hindered bythe second piezoelectric material when the first piezoelectric materialis driven and the deformation in horizontal direction occurs, or viceversa.

The plurality of first and second piezoelectric materials may bearranged on the same layer. Referring to FIG. 23, the rows (V1, V2, V3)on which the second piezoelectric materials are arranged may be arrangedbetween the first piezoelectric materials to allow proper connectionbetween the piezoelectric materials and the electrode patterns.

When the different types of piezoelectric materials with differentdirections of longer axes are provided together, the flexible device 100is able to deform not only horizontally, but also vertically.

Although FIG. 23 illustrates an example in which the first and secondpiezoelectric materials are arranged on the same layer, thepiezoelectric materials may be arranged on different layers from eachother.

FIG. 24 is a cross-section of a flexible device including a plurality ofpiezoelectric materials distributed to different layers. Referring toFIG. 24, a plurality of layers 126-1, 126-2 are sequentially stacked onone surface of the display 120. The plurality of piezoelectric materialsare distributed over the plurality of layers 126-1, 126-2.

FIG. 24 is a cross section cut along a column-wise direction of theflexible device 1000. Referring to FIG. 24, the first piezoelectricmaterials 110-H11, 110-H12, 110-H13, 110-H14 aligned in column-wisedirection are successively arranged on the upper layer 126-1, while thesecond piezoelectric materials 110-V11, 110-V21, 110-V31 aligned inrow-wise direction are arranged on the lower layer 126-2.

When the first piezoelectric materials to deform column-wisely and thesecond piezoelectric materials to deform row-wisely are arranged ondifferent layers from each other, the electrode pattern can besimplified.

FIG. 25 illustrates a piezoelectric material arrangement pattern inanother exemplary embodiment. Referring to FIG. 25, the plurality ofpiezoelectric materials 110-1˜110-14 are successively aligned incolumn-wise direction. The piezoelectric materials 110-1, 110-2, 110-3,110-4, 110-8, 110-9, 110-10, 110-11 included in the odd-numbered columns(H1, H3), and the piezoelectric materials 110-5, 110-6, 110-7, 110-12,110-13, 110-14 included in the even-numbered columns (H2, H4) arecrossed to each other.

The flexible device that includes the piezoelectric materials in thepattern as illustrated in FIG. 25 is able to adjust the degree ofdeformation without having to adjust the size of the drive signal, byadjusting the driving of the piezoelectric materials in respectivecolumns. To be specific, to roll the flexible device 1000, thecontroller 130 may drive the piezoelectric materials of the entirecolumns. On the contrary, to set a smaller degree of deformation, thecontroller 130 may only drive the odd-numbered or even-numbered columns.

In the exemplary embodiment illustrated in FIG. 25, the respectivepiezoelectric materials may be distributed over the different layers.FIG. 26 is a cross-section view of a flexible device includingpiezoelectric materials which are distributed over a plurality oflayers.

Referring to FIG. 26, the piezoelectric materials 110-1, 110-2, 110-3,110-4 corresponding to the odd-numbered columns are arranged on theupper layer 126-1, while the piezoelectric materials 110-5, 110-6, 110-7corresponding to the even-numbered columns are arranged on the lowerlayer 126-2.

Meanwhile, referring to FIG. 25, the flexible device 1000 may benddiagonally, when the electrode patterns are connected in the unit ofpiezoelectric materials as illustrated in FIG. 14.

For example, the second, fifth and eighth piezoelectric materials 110-2,110-5, 110-8 exclusively bend, when the controller 130 applies drivesignal to the second, fifth and eighth piezoelectric materials 110-2,110-5, 110-8, and not to the rest piezoelectric materials. As a result,a bending line is formed, connecting the second, fifth, and eighthpiezoelectric materials 110-2, 110-5, 110-8, so that the deformationoccurs with reference to the bending line, in which the left cornerbends upward or downward.

While the exemplary embodiments explained above have piezoelectricmaterials arranged with longer axes aligned to column-wise or row-wisedirections, the arrangement pattern of the piezoelectric materials mayvary. For example, the longer axes of the piezoelectric materials may bealigned in diagonal direction. Further, instead of being distributed tothe entire area of the body 100 of the flexible device 1000, thepiezoelectric materials may be successively arranged along an edge areain one or two lines.

FIG. 27 is a flowchart provided to explain an operating method of aflexible device according to an exemplary embodiment. Referring to FIG.27, when a preset event occurs at S2710, the flexible device 1000applies a corresponding driving signal to the respective piezoelectricmaterials corresponding to the event, at S2720.

As explained above, the piezoelectric material may include upper andlower piezoelectric layers. The drive signal may be individuallydetermined for the respective piezoelectric materials, depending on thetype of the event. That is, the operation to apply drive signal mayinclude individually determining drive signals to apply to upper andlower piezoelectric layers within the plurality of piezoelectricmaterials, depending on the type of event, and applying the determineddrive signals to the upper and lower piezoelectric materials.

With the application of the drive signals, the respective piezoelectricmaterials deform. The direction of deformation is, as explained above,determined by the relationship between the drive signals applied to theupper and lower piezoelectric layers. At S2730, when the respectivepiezoelectric materials deform, the shape of the body 100 of theflexible device deforms where the piezoelectric materials are arrangeddeform. The shape of the body 100 may be deformed variously, dependingon the location of the driven piezoelectric materials, polarity of thedrive signals, or magnitude of the drive signals. The arrangementpattern or method for driving the piezoelectric materials will not beadditionally explained below, but referenced to the above correspondingexplanations.

Meanwhile, as explained above, the piezoelectric materials may becategorized into a plurality of groups according to locations thereof,in which case it is possible to locally deform the flexible device byapplying different drive signals to the respective groups.

The flexible device 1000 may automatically deform to suit variousservices the flexible device 1000 provides. The flexible device 1000 maybe implemented as a variety of devices. For example, the flexible device1000 may be implemented as a mobile phone, a PDA, a laptop computer, aMP3 player, an e-book device, a remote controller, or any new form ofdevice.

FIG. 28 is a view provided to explain a constitution of the flexibledevice 1000 according to another embodiment. Referring to FIG. 28, theflexible device 1000 includes a plurality of piezoelectric materials110-1˜110-n, a display 120, a controller 130, a storage 140, a driver150, a bus 160, a sensor 170, a detector 180, a communicator 190, avideo processor 210, an audio processor 220, a button 230, a speaker240, interfaces 250-1˜250-m, a camera 260, and a microphone 270.

The constitution and operation of the plurality of piezoelectricmaterials 110-1˜110-n, the display 120, the controller 130, the storage140, the driver 150, and the bus 160 will not be additionally explainedbelow.

As explained with reference to FIG. 22, the sensor 170 may include abiosensor arranged on one side of the body 100 to detect presence oftouch by an operator's body (OB).

The sensor 170 may additionally include electromagnetic sensor, a gyrosensor, an acceleration sensor or a touch sensor. The electromagneticsensor senses rotational status and direction of movement of theflexible device 1000. The gyro sensor detects rotational angle of theflexible device 1000. Both the electromagnetic sensor and the gyrosensor may be provided, but it is possible to detect the rotationalstatus of the flexible device 1000 even when only one of these isprovided. The acceleration sensor operates to sense the degree oftilting of the flexible device 1000. The touch sensor may be capacitiveor resistive. The capacitive sensor uses dielectric material coated onthe surface of the display 120 to sense microcurrent excited by theoperator's body touching the surface of the display 120, and calculatetouch coordinates. The resistive sensor includes two electrode plates sothat, when the operator touches the screen, the contact between theupper and lower plates at the touched spot enables detection of thecurrent flow and calculation of touch coordinates. As explained above,the touch sensor may be variously implemented. The touch sensor may bearranged on the rear surface of the flexible device 1000 and used tosense the operator's touch. The biosensor may be omitted, when the touchsensor is provided on the rear surface.

The detector 180 is connected to the respective piezoelectric materials110-1˜110-n to detect a signal from the piezoelectric materials. Whenthe operator bends the body 100, pressure is exerted on thepiezoelectric materials 110-1˜110-n at the bent area. As explainedabove, under the pressure, the piezoelectric materials 110-1˜110-ngenerate piezoelectric effect. As a result, the piezoelectric materials110-1˜110-n generate electric signal in size corresponding to thepressure.

The controller 130 determines the deformation state of the body 100based on the change in the electric signal as detected at the detector180. To be specific, based on the location of the piezoelectricmaterials 110-1˜110-n where the change of electric signal is detected,the controller 130 determines the area having deformed. Referring toFIG. 2, when the respective piezoelectric materials 110-1˜110-n arearranged on the rear surface of the flexible device 1000, thecompressive force is exerted on the upper piezoelectric layer and thetensile force is exerted to the lower piezoelectric layer, upon bendingto the direction of the display 120. In this case, (+) polarity electricsignal is outputted from the piezoelectric materials 110-1˜110-n. Withthe bending in opposite direction, the piezoelectric materials110-1˜110-n output (−) polarity electric signal. Based on the polarityof the electric signal as detected from the piezoelectric materials110-1˜110-n, the controller 130 determines the direction of bending.Further, the controller 130 is able to determine intensity ofdeformation based on the size of electric signal. Further, thecontroller 130 may determine deformation duration, by counting the timeduration of detecting the electric signal.

As explained above, when determining area, direction, intensity or timeof bending are determined, the controller 130 may determine thedeformation state of the flexible device 1000 by comprehensivelyanalyzing the determined results. The deformation state may includegeneral bending, folding, multi-bending, bending and move, bending andflat, bending and hole, bending and twist, twist, swing, shaking,rolling, or various others.

The storage 140 stores information about controlling operationcorresponding to the respective deformation state. The controller 130performs corresponding control operation according to the deformationstate, based on the information stored at the storage 140. To bespecific, the controller 130 may perform operation including, forexample, turn-on, turn-off, channel zapping, volume adjustment,application execution, cursor moving, content playback, web browsing,page shifting, screen quality adjustment, or various other operations.

The communicator 190 is configured to perform communication with varioustypes of external devices according to various types of communicationmethods. The communicator 190 may include a WiFi chip 191, a Bluetoothchip 192, an NFC chip 193, a wireless communication chip 194 or variousother communication chips.

The WiFi chip 191, the Bluetooth chip 192, and the NFC chip 193 mayperform communication by WiFi, Bluetooth and NFC methods. The NFC chip193 operates by near field communication (NFC) manner, using 13.56 MHzamong various RF-ID frequency bands such as 135 kHz, 13.56 MHz, 433 MHz,860˜960 MHz, 2.45 GHz. When the WiFi chip 191 or Bluetooth chip 192 isused, the connection-related information, such as SSID and session key,may be first transmitted and received so that communication is connectedfor information transmission and reception. The wireless communicationchip 194 performs communication according to various communicationspecifications such as IEEE, Zigbee, 3rd generation (3G), 3rd generationpartnership project (3GPP), or long term evolution (LTE).

The flexible device 1000 may additionally include a global positioningsystem (GPS) chip or digital multimedia broadcasting (DMB) receivingmodule.

The video processor 210 handles video data processing. The videoprocessor 210 may perform various image processing such as, for example,decoding, scaling, noise filtering, frame rate conversion, or resolutionconversion of the video data.

The audio processor 220 handles audio data processing. The audioprocessor 220 may perform various processing of audio data such as, forexample, decoding, amplification, noise filtering, or others.

The audio and video processors 220, 210 are used to process and playbackmultimedia content or DMB signal.

The display 120 displays video frames processed at the video processor210. The speaker 240 is configured to output not only the various audiodata processed at the audio processor 220, but also various alarm soundsor voice messages.

The button 230 may include various types of buttons such as a mechanicbutton, touch pad, or wheel formed on a predetermined area such asfront, side or rear side of the outer portion of the body of theflexible device 1000.

The camera 260 is configured to capture still or video images accordingto control of the user. A plurality of cameras 260 including frontcamera and rear camera may be provided.

The microphone 270 is configured to receive user voice or other soundsand convert the same into audio data. The controller 130 may use theuser voice inputted through the microphone 270 during a call, or convertthe same into audio data and stored at the storage 140.

When the camera 260 and the microphone 270 are provided, the controller130 may perform a control operation according to a user voice asinputted through the microphone 270 or a user motion as perceivedthrough the camera 260. That is, the flexible device 1000 may operate inmotion control mode or voice control mode, in addition to beingcontrolled according to deformation or touch. When operating in motioncontrol mode, the controller 130 may activate the camera 260 to capturethe user, trace the change in the user's motion and accordingly performcontrol operation. When in voice control mode, the controller 130 mayoperate in voice recognition mode to analyze the user voice as inputtedthrough the microphone 270 and control according to the analyzed uservoice. The controller 130 may control the driver 150 to drive therespective piezoelectric materials 110-1˜110-n based on the user voice,user motion or button 230 manipulation. Accordingly, the form of theflexible device 1000 is deformed appropriately according to the usercontrol.

Additionally, various interfaces 250-1˜250-m may be provided to connectto various external terminals such as headset, mouse, or LAN. Further,although not illustrated, the flexible device 1000 may additionallyinclude a power source (not illustrated). The power source supplieselectricity to the respective components of the flexible device 1000.The power source may be flexible so as to bend along with the flexibledisplay apparatus 100. In such a situation, the current collector,electrode, electrolyte, or clad may be formed from a flexible material.

Meanwhile, the operation of the controller 130 as explained above may beperformed according to the program stored at the storage 140. Thestorage 140 may store various data including, for example, O/S softwareto drive the flexible device 1000, various applications, data inputtedor set during execution of the applications, contents, bending gesture,or drive information of the pm.

The controller 130 controls the overall operations of the flexibledevice 1000 using the various programs stored at the storage 140.

The controller 130 may include a read only memory (ROM) 131, a randomaccess memory (RAM) 132, a central processing unit (CPU) 133, a graphicprocessing unit (GPU) 134, and a system bus 135.

The ROM(131), RAM(132), CPU(133), and GPU(134) may be connected to eachother via the system bus 135.

The CPU 133 accesses the storage 140 and performs booting using the O/Sstored at the storage 140. The CPU 133 performs various operations usingthe programs, contents or data stored at the storage 140.

The ROM 131 stores a command set for system booting. When electricity issupplied in response to turn-on command, the CPU 133 copies the O/Sstored at the storage 140 onto the RAM 132, executes the O/S and bootsup the system, according to the command stored at the ROM 131. Whenbooting completes, the CPU 133 copies various application programsstored at the storage 140 onto the RAM 132, and executes the copiedapplication programs of the RAM 132 to perform various operations.

When the above-mentioned event occurs, the CPU 133 transmits addressinformation, direction information, drive signal information, etc. ofthe piezoelectric materials 110-1˜110-n to deform to the driver 150 sothat the body 100 deforms according to the event. The driver 150generates a drive signal to be applied to the respective piezoelectricmaterials 110-1˜110-n and outputs the same according to the control ofthe CPU 134.

Further, when a detect signal corresponding to the deformation state isreceived from the detector 180, the CPU 133 determines the deformationstate that corresponds to the detect signal. Upon completing thedetermination, the CPU 133 confirms through the storage 140 theinformation about the function that matches the deformation state, andloads the application to perform the function from the RAM 132 andexecutes the same.

The GPU 134 generates a screen including various objects such as icons,images or text, using the calculator (not illustrated) and the renderer(not illustrated). The calculator calculates attribute values, such ascoordinates, configuration, size or color, to display the respectiveobjects according to the screen layout. The renderer generates screensof various layouts including objects therein, based on the attributevalues as calculated at the calculator. The screens generated at therenderer are displayed within the display area of the display 120.

As explained above with reference to FIG. 28, when piezoelectricmaterials are provided, the shape of the flexible device may beautomatically deformed using the piezoelectric materials, or the currentdeformation state may be detected using the piezoelectric materials. Asa result, without having to use separate bend sensors, it is possible toeasily determine to which shape the deformation occurs.

Meanwhile, FIG. 28 illustrates the respective components of the flexibledevice implemented as an apparatus incorporating therein multiplefunctions including communication, broadcasting, and video playback.Accordingly, depending on embodiments, some of the componentsillustrated in FIG. 28 may be omitted or modified, or other componentsmay be added.

As explained above, the controller 130 may perform various operations byexecuting the programs stored at the storage 140.

FIG. 29 is a view provided to explain a constitution of the softwarestored at the storage 140. Referring to FIG. 29, the storage 140 maystore software that includes a base module 141, a sensing module 142, acommunication module 143, a presentation module 144, a web browsermodule 145, and a service module 146.

The base module 141 processes signals transmitted from the hardwareincluded in flexible device 1000 and transmits the same to the upperlayer module.

The base module 141 includes a storage module 141-1, a location-basedmodule 141-2, a security module 141-3, and a network module 141-4.

The storage module 141-1 manages database (DB) or registry. The CPU 133accesses the database within the storage 140 using the storage module141-1 to read out various data. The location-based module 141-1 is aprogram module that supports location-based service in association withvarious hardware such as GPS chip, or the like. The security module141-3 is a program module that supports certification, permission, orsecure storage of the hardware, and the network module 141-4 supportsnetwork connection and includes DNET module, or UPnP module.

The sensing module 142 collects information from the respective sensorsof the detector 180, analyzes and manages the collected information. Tobe specific, the sensing module 142 performs detection of manipulationattributes such as coordinates of the point of touch, direction ofmoving touch, velocity of movement, or distance of movement. Dependingon embodiments, the sensing module 142 may include rotation recognitionmodule, voice recognition module, touch recognition module, motionrecognition module, or bending recognition module. The bendingrecognition module is the software that analyzes detect signal at thedetector 180 to determine deformation state in the manner explainedabove.

The communication module 143 performs communication with outside. Thecommunication module 143 may include a messaging module 143-1 such as amessenger program, a short message service (SMS) & multimedia messageservice (MMS) program, or e-mail program, or a call module 143-2 such asa call info aggregator program module, or a VoIP module.

The presentation module 144 constructs a display screen. Thepresentation module 144 includes a multimedia module 144-1 to playbackand output multimedia content, and a UI rendering module 144-2 toprocess UI and graphics. The multimedia module 144-1 may include aplayer module, a camcorder module, or a sound processing module.Accordingly, the presentation module 144 plays back various multimediacontents and generates and plays screen and audio. The UI renderingmodule 144-2 may include an image compositor module which composeimages, a coordinate combine module which combines coordinates on ascreen to display an image, an XII module which receives various eventsfrom the hardware, or a 2D/3D UI toolkit which constructs 2D or 3D UI.

The web browser module 145 web-browsers and accesses web server. The webbrowser module 145 may include various modules such as web view moduleto construct a web page, a download agent module to perform downloading,a bookmark module, or webkit module.

The service module 146 includes various applications to provide servicesthat match a manipulation, when the user manipulation such asdeformation, user voice, motion, touch, button manipulation is inputted.For example, the service module 146 may include word program, e-bookprogram, calendar program, game program, schedule management program,alarm management program, content playback program, navigation program,or widget program. When the programs executed accompany deformation, thecontroller 130 controls the driver 150 to ensure that the deformationoccurs as indicated by the program. The examples of the deformation willnot be redundantly explained, but referenced to the above correspondingdescription.

Although various program modules are illustrated in FIG. 29, the programmodules as illustrated may be partially omitted, modified, or some maybe added, depending on types and characteristics of the flexible device1000. For example, when the flexible device 1000 is implemented as aremote controller type with flexibility and control function on externaldevices, and without display function, the modules such as thepresentation module 144, the web browser module 145 or the servicemodule 146 may be omitted. In this case, the module to detectcharacteristic of the deformation state, and registry to designateinformation on the control signal matching the detected result may bestored at the storage 140 for use.

Meanwhile, as explained above, the flexible device 1000 may use both thefirst and second piezoelectric effects of the piezoelectric materials.

FIG. 30 is a flowchart provided to explain an operation method of aflexible device using the first piezoelectric effect.

Referring to FIG. 30, at S3010, the flexible device constantly monitorsto detect electric signals at the respective piezoelectric materials.When the electric signals are detected, at S3020, the flexible device1000 checks the deformation state that corresponds to the changecharacteristic of the electric signals. The method for determiningdeformation state will not be redundantly explained below.

At S3030, upon checking the deformation state, the flexible device 1000performs a control operation corresponding to the state. Since theexamples of the deformation state and control operations correspondingthereto have been also explained above, this is also omitted below forthe sake of brevity.

As explained above, according to various exemplary embodiments, it ispossible to freely deform the flexible device 1000 using a plurality ofpiezoelectric materials arranged in the flexible device 1000.

Further, since it is possible to detect the deformation state of theflexible device 1000 using the piezoelectric materials, the user is ableto select and execute various functions by deforming manipulation.

As a result, utilization and user satisfaction of using flexible deviceimprove.

Meanwhile, the operation method of the flexible device according tovarious exemplary embodiments may be implemented as a program for use inthe flexible device.

To be specific, a non-transitory computer readable medium storingtherein a program may be provided, in which the program includes stepsof determining whether or not a preset event occurs, and when the eventoccurs, applying a drive signal individually to a plurality ofpiezoelectric materials mounted at different locations of the flexibledevice.

The non-transitory computer readable medium refers to a medium which isreadable by a device and which stores data semi-permanently, instead ofthat which briefly stores the data such as register, cache, or memory.To be specific, the various applications or programs as explained abovemay be stored and provided on the non-transitory computer readablemedium such as CD, DVD, hard disk, blu-ray disk, USB, memory card, orROM.

The foregoing exemplary embodiments and advantages are merely exemplaryand are not to be construed as limiting the exemplary embodiments. Thepresent teaching can be readily applied to other types of apparatuses.Also, the description of the exemplary embodiments of the presentinventive concept is intended to be illustrative, and not to limit thescope of the claims.

What is claimed is:
 1. A flexible device comprising: a flexible body; aflexible display panel supported by the flexible body; a first layercomprising a first plurality of piezoelectric materials and a firstplurality of electrode patterns, wherein a longer axis of each of thefirst plurality of piezoelectric materials is arranged in a horizontaldirection of the flexible device and the first plurality of electrodepatterns commonly connect piezoelectric materials of a respective row ofrows comprising the first plurality of piezoelectric materials; a secondlayer comprising a second plurality of piezoelectric materials and asecond plurality of electrode patterns, wherein a longer axis of each ofthe second plurality of piezoelectric materials is arranged in avertical direction of the flexible device and the second plurality ofelectrode patterns commonly connect piezoelectric materials of arespective column of columns comprising the second plurality ofpiezoelectric materials; a storage configured to store information of aplurality of deformation states and information on a plurality ofapplications being matched with the plurality of deformation states,respectively; and a controller configured to: in response to executing afirst application among the plurality of applications, apply a firstdrive signal to the first plurality of piezoelectric materials throughthe first plurality of electrode patterns of the first layer based on afirst deformation state being matched with the first application suchthat the flexible device is deformed to the first deformation statebased on a deformation of the first plurality of piezoelectric materialsaccording to the first drive signal, and in response to executing asecond application among the plurality of applications, apply a seconddrive signal to the second plurality of piezoelectric materials throughthe second plurality of electrode patterns of the second layer based ona second deformation state being matched with the second applicationsuch that the flexible device is deformed to the second deformationstate based on a deformation of the second plurality of piezoelectricmaterials according to the second drive signal.
 2. The flexible deviceof claim 1, wherein the controller is configured to: identify adeformation state of the flexible body based on electric signalsgenerated from at least one of the first plurality of piezoelectricmaterials and the second plurality of piezoelectric materials, and basedon a change of at least one of the electric signals being detected,identify the deformation state of the flexible body using the changed atleast one of the electric signals.
 3. The flexible device of claim 2,wherein the controller is configured to identify a bent area of theflexible body based on a location of a piezoelectric material where thechange of the electric signals is detected from among the firstplurality of piezoelectric materials and the second plurality ofpiezoelectric materials.
 4. The flexible device of claim 2, wherein thecontroller is configured to identify an intensity of deformation of theflexible body based on a value of at least one of the electric signalsgenerated from the first plurality of piezoelectric materials and thesecond plurality of piezoelectric materials.
 5. The flexible device ofclaim 2, wherein the controller is configured to identify deformationduration based on a time duration of the electric signals generated fromthe first plurality of piezoelectric materials and the second pluralityof piezoelectric materials.
 6. The flexible device of claim 2, whereinthe deformation state includes at least one of general bending, folding,multi-bending, bending and move, bending and flat, bending and hold,bending and twist, twist, swing, shaking, and rolling.
 7. The flexibledevice of claim 2, wherein the controller is configured to perform acontrol operation corresponding to the identified deformation state, thecontrol operation including at least one of turn-on, turn-off, channelzapping, volume adjustment, application execution, cursor moving,content playback, web browsing, page shifting, and screen qualityadjustment.